Your 'pearl pendulum' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
** Your general comment, if any: **
** Your description of the rhythm of the pendulum when tilted 'back' **
With each passing bounce, the time between each bounce shortens. That means that the fake pearl hits the bracket more frequently and the rhythm gets faster.
** Your description of the rhythm of the pendulum when tilted 'forward' **
When I tilt the bracket forward, the fake pearl hits the bracket at the same pace. It moves the same distance, and it maintains a steady rhythm for a few seconds until it stops.
** Your description of the process used to keep the rhythm steady and the results you observed: **
I took an old notepad in my house, and put that underneath the bracket. Now when I move the fake pearl away, it will strike the bracket at a constant rhythm. It moves for a few seconds before it comes to a complete stop.
** Your description of what happened on the tilted surface (textbook and domino), rotating the system 45 degrees at a time: **
There is a domino under the top left of the textbook(cover facing upward) and bottom right of the textbook. The textbook is positioned as if I would be reading it. The bracket with the fake pearl is facing me. When I release it, the sounds get closer together.
When I tilt it 45 degrees counterclockwise, the sound stays the same.
When I tilt the bracket another 45 degrees so that it is 90 degrees from the original position, the sound stays the same.
When I tilt the bracket 45 degrees, the sound stays the same.
When I tilt the bracket so it is 180 degrees from the original position, the beat speeds up.
When I tilt the bracket another 45 degrees, the rhythm stays constant.
When I tilt the bracket 45 degrees so that it is 270 degrees from the original position, the rhythm slows down.
When I tilt the bracket 45 degrees, the rhythm slows down.
** Your description of how you oriented the bracket on the tilted surface to obtain a steady rhythm: **
When the bracket is on the textbook with two dominoes on the upper left and bottom right of the book, the beat will remain the same when the bracket will face the bottom right 45 degrees from the original position.
** Your report of 8 time intervals between release and the second 'hit': **
0.484
0.297
0.376
0.455
0.399
0.388
0.412
0.378
These numbers are the number of seconds it took for the fake pearl to be released and hit the bracket a second time. This is the time it took to hit the bracket twice.
** Your report of 4 trials timing alternate hits starting with the second 'hit': **
0.383, 0.328. 0.578, 0.621
0.352, 0.453
0.441, 0.656, 0.703, 0.719
0.344, 0.488, 0.563, 0.621
** The length of your pendulum in cm (you might have reported length in mm; the request in your instructions might have been ambiguous): **
8.29cm
** Your time intervals for alternate 'hits', starting from release until the pendulum stops swinging: **
0.38, 0.481, 0.615, 0.654
** Your description of the pendulum's motion from release to the 2d hit: **
The pearl is let go from one side, striked the bracket, which is usually the middle of a pendulum. It then moves back to its original position.
** Your description of the pendulum's motion from the 2d hit to 4th hit: **
After the first hit, the fake pearl moves close to the equilibrium point and goes back to hit the bracket. It does not travel as far as it did before. Depending on how the bracket is leveled, it may either hit the bracket at about the same time as the first hit, or it may speed up or slow down.
** Your description of the difference in the pendulum's motion from release to the 2d 'hit', compared to the motion from the 2d 'hit' to the 4th hit: **
The distance traveled of the pearl decreases more and more after every hit until it stops moving.
** Your description of the difference in the pendulum's motion from the 2d to the 4th 'hit' compared to the motion from the 4th to 6th hit: **
The distance traveled of the pearl decreases more and more after every hit until it stops moving.
** Your conjecture as to why a clear difference occurs in some intervals vs. others: **
The pearl is given a higher initial velocity when gravity kicks in after I let go of the pearl.
** What evidence is there that subsequent intervals increase, decrease or remain the same: **
This depends on how the bracket is leveled. If the marble hits it at the same rate, the time intervals should remain close together. This is what happened when I timed the experiment. There have been instances in this experiment where if I measured the time, it would have shortened or lengthened.
** What evidence is there that the time between 'hits' is independent of the amplitude of the swing? **
The time it took for the pendulum to continuously strike the bracket remained about the same regardless of how far the pendulum swung.
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1 hour
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&#Your work looks good. Let me know if you have any questions. &#